Field of the Invention
The invention relates to a radiator fan of a motor vehicle, in particular a main fan, having a fan wheel, which has a hub, and has an electric-motor rotor attached thereto.
During operation, motor vehicles having an internal combustion engine exhibit considerable heat generation. To maintain the operating temperature of the internal combustion engine and also to operate an air conditioning system, use is generally made of a liquid coolant, which must, in turn, be cooled. This is generally accomplished by a radiator system, which is acted upon by a relative wind and which is in a relationship of heat exchange with the coolant. For example, the coolant is passed into tubes that are incorporated into the radiator system. Since the relative wind is normally insufficient for cooling, particularly at low vehicle speeds, published, European patent application EP 1 621 773 A1 (corresponding to U.S. Pat. No. 7,042,121), for example, discloses the use of an electric fan, by which the relative wind is intensified.
Here, the fan is arranged behind the radiator system in the direction of travel. With the aid of a fan wheel of the fan, air is sucked through the radiator system and directed at the internal combustion engine. If there is a condenser system of a condenser of an air-conditioning system in addition to the radiator system, the condenser system is generally arranged ahead of the radiator system in the direction of the relative wind.
The fan wheel is connected to a rotor shaft of the electric motor or the rotor thereof by a central rotor shaft clutch. Other conventional measures of fastening the fan wheel to the rotor have screws. These are screwed into the rotor through the fan wheel from the side thereof facing away from the electric motor. Generally, three such screws are used. It is furthermore known to join the fan wheel to the rotor shaft by press fitting or to fix them to one another by a bayonet joint.